A pressure-regulating valve is known in the art, and such a valve includes, for example, a valve controlled by a control unit, using which a gas having a specified pressure may be made available to a downstream user unit. If, for instance, a pulse valve is used, sufficiently good valve dynamics are ensured, but not for all applications.
It is also known in the art that, to prepare a gas having a certain pressure, a pressure regulator module may be equipped with a diaphragm valve. However, a diaphragm valve has a drawback in that it supplies an outlet pressure which is a function of the gas pressure made available at the valve inlet, which may have a disadvantageous effect, particularly in the case of falling inlet pressures.
In motor vehicles which have a gas engine or even a fuel cell, it is necessary to be able to store as great a gas quantity as possible in an appropriate tank. For this purpose, the respective gas, such as natural gas or hydrogen is put under high pressure in a tank, e.g., in the case of a gas engine fueled by natural gas, under a pressure of about 250 bar to 300 bar, and, in the case of a fuel cell fueled by hydrogen, under a pressure of about 700 bar to 750 bar. Downstream from the tank, the gas pressure in each case has to be reduced to a system pressure that is needed by the respective user, e.g., of about 4 bar to 8 bar. As a rule, this is implemented by using a pressure-regulating module of the type described above. During operation, the gas pressure goes down in the respective tank, from a maximum pressure when the tank is full, to a pressure of about 10 to 20 bar.
In the pressure regulating modules that have been used up to this point, this phenomenon disadvantageously changes the dynamics of the modules, since the dynamics are a function of the inlet pressure, and consequently change with the filling state of the tank.